Sorry if I'm being Captain Obvious, If you can spare to do it, which it hasn't been a problem with me, turn off 3G Mobile connect. Turn on as needed, simplest way to do this is to add a widget to the home screen. Do as follows: + button, widget, settings, Mobile Network you could also long press the home to add this widget, now just turn on and off as needed. I have used this method for about a week and have had good results, sometimes not even needing to charge overnight. I have WiFi at home so that helps tremendously, I just use WiFi at home and when I'm on the road and need it I turn on the Mobile network. Works like a charm, try this out and let me know if it works for anyone else.